Question:
List all the elements of each of the sets given below.
A = {x : x = 2n, n ϵ N and n ≤ 5}.
Solution:
Given: x = 2n and n ≤ 5
$\Rightarrow \mathrm{n}=1,2,3,4$ and $5[\because \mathrm{n} \in \mathrm{N}]$
Given $x=2 n$
$n=1, x=2 \times 1=2$
$n=2, x=2 \times 2=4$
$n=3, x=2 \times 3=6$
$n=4, x=2 \times 4=8$
$n=5, x=2 \times 5=10$
So, the elements of A are 2, 4, 6, 8 and 10
∴, A = {2, 4, 6, 8, 10}